CVE-2026-3663

xlnt-community xlnt XLSX File compound_document.cpp xsgetn out-of-bounds

HIGH
7.1
CVSS Score
Published: March 7, 2026 at 02:32 PM UTC
Updated: June 17, 2026 at 10:43 AM UTC
1 product affected across 1 vendorXlnt

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Severity
HIGH7.1
Exploit prediction
EPSS 0.2%
SSVC
No known exploit

Description

A vulnerability was found in xlnt-community xlnt up to 1.6.1. This issue affects the function xlnt::detail::compound_document_istreambuf::xsgetn of the file source/detail/cryptography/compound_document.cpp of the component XLSX File Parser. Performing a manipulation results in out-of-bounds read. The attack is only possible with local access. The exploit has been made public and could be used. The patch is named 147. It is recommended to apply a patch to fix this issue.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (7)

VDB EntryTechnical DescriptionThird Party Advisory
Source: cverecord
https://vuldb.com/?id.349552
SignaturePermissions RequiredVDB Entry
Source: cverecord
https://vuldb.com/?ctiid.349552
Third Party AdvisoryVDB Entry
Source: cverecord
https://vuldb.com/?submit.764644
Issue TrackingExploitVendor Advisory
Source: cverecord
https://github.com/xlnt-community/xlnt/issues/139
Issue TrackingPatch
Source: cverecord
https://github.com/xlnt-community/xlnt/pull/147

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

Attack Vector
LOCAL
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusANALYZED
CWE
CWE-125CWE-119

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